QueryStringQueryBuilder queryStringBuilder = QueryBuilders.queryString(queryString);
queryStringBuilder.defaultField(request.param("df"));
queryStringBuilder.analyzer(request.param("analyzer"));
queryStringBuilder.analyzeWildcard(request.paramAsBoolean("analyze_wildcard", false));
queryStringBuilder.lowercaseExpandedTerms(request.paramAsBoolean("lowercase_expanded_terms", true));
queryStringBuilder.lenient(request.paramAsBoolean("lenient", null));
String defaultOperator = request.param("default_operator");
if (defaultOperator != null) {
if ("OR".equals(defaultOperator)) {
queryStringBuilder.defaultOperator(QueryStringQueryBuilder.Operator.OR);
} else if ("AND".equals(defaultOperator)) {